We investigated emotional conflict in an educational context with an emotional body–word Stroop paradigm, examining whether the N450 (a late fronto-central phasic negative event-related potential signature) and slow potential (SP) effects could be evoked in trainee teachers. The N450 effect is characterized by topography and negative polarity of an incongruent minus congruent difference potential, and the SP effect has positive polarity (incongruent minus congruent difference potential). Positive and negative body language examples were obtained from pupils in an actual school context, and emotional words were selected. Compound stimuli were presented, each comprising a congruent or incongruent word displayed across a body image. Event-related potentials were recorded while participants judged body expression valence. Reaction times were longer and accuracies were lower for the incongruent compared to the congruent condition. The N450 component amplitude in the incongruent condition was more negative than in the congruent condition. Results showed a behavioral interference effect and an N450 effect for trainee teachers in this context, thus indicating that the body–word task was efficient in assessing emotional conflict in an educational context, and trainee teachers' perception of body expressions of students could be influenced by emotional signals. The findings further the understanding of emotional conflict in an educational context.